In general, this application is directed to novel diketopiperazines, their use in inhibiting cellular events involving TNF-xcex1, e.g., NFK-xcex1 and/or NFK-xcex2, IL-8, GRO-xcex1, CXCR1, CXCR2 and treatment of inflammation events in general.
The process of discovering new therapeutically active compounds for a given indication often involves the screening of compounds from available compound collections. From the compounds tested one or more structures is selected as a promising lead. A number of related analogues are then synthesized in order to develop a structure-activity relationship and select one or more optimal compounds. Following traditional one-at-a-time synthesis and biological testing of analogues, this optimization process is time consuming and labor intensive. Adding significant numbers of new structures to the compound collections used in this initial screening step of the discovery and optimization process cannot be accomplished with traditional one-at-a-time synthesis methods, except over a time frame of months or even years. Faster methods are needed that allow for the preparation of libraries of related compounds in a matter of days or a few weeks. This need is particularly evident when it comes to synthesizing more complex compounds, such as diketopiperazines.
Combinatorial approaches have recently been extended to xe2x80x9corganicxe2x80x9d or non-peptide, libraries. There is a need in the art for new and diverse organic libraries, which may be used in screening processes.
Although treatment regimens are available for the symptomatic amelioration of diseases such as rheumatoid arthritis, asthma, inflammatory bowel disease, allergic inflammation of respiratory pathways, cancer, atherosclerosis, sepsis, adult respiratory distress syndrome, reperfusion injury, graft vs. host disease, multiple sclerosis, severe invasive infections such as fulminant hepatitis, AIDS and bacterial meningitis, there still exists the need for a composition and method for preventing and/or treating the inflammation which is often associated with the disease.
This invention satisfies these needs and provides related advantages as well. The present invention overcomes the known limitations to classical organic synthesis of diketopiperazines, the shortcomings of combinatorial chemistry as directed to diketopiperazines, and provides compounds which are useful in inhibiting TNF-xcex1, TNF-xcex2, I1-8 and apoptotic mediated processes, and other inflammation-resultant situations. Moreover, this invention provides a library of diverse diketopiperazines useful in elucidating structure-function relationships in biological processes, such as inflammation.
In one aspect, the present invention provides a diketopiperazine (DKP) compound of the structure (I): 
and optical isomers, diastereomers, enantiomers and pharmaceutically acceptable salts thereof in isolation or mixture, where, independently at each location: R1 is an aryl or heteroaryl ring; R2 and R3 are selected from hydrogen, alkyl, heteroalkyl, aryl, heteroaryl, carbocycle aliphatic ring, and heterocycle aliphatic ring; n is 1, 2 or 3; R4 is selected from xe2x80x94OR5 and xe2x80x94NR6R7, R5 is selected from hydrogen, alkyl, heteroalkyl, aryl, heteroaryl, carbocycle aliphatic ring and heterocycle aliphatic ring; and R6 and R7 are independently selected from hydrogen, alkyl heteroalkyl, aryl, heteroaryl, carbocycle aliphatic ring and heterocycle aliphatic ring or R6 and R7 taken together with the nitrogen atom to which they are attached form a heterocycle aliphatic ring.
In other aspects, the present invention provides a DKP compound of structure (1) wherein R1 is phenyl and the phenyl is substituted with 1-4 substituents independently selected at each occurrence from alkyl, heteroalkyl, aryl, heteroaryl, carbocycle aliphatic ring, heterocycle aliphatic ring. In other aspects, the present invention provides a DKP compound of structure (1) wherein R1 is phenyl having a substituent at the position para to the site of attachment to the piperazine ring.
In other aspects, the present invention provides a DKP compound of structure (1) wherein R1 is phenyl having a substituent at the position para to the site of attachment to the piperazine ring, and the substituent has the formula R10xe2x80x94R9xe2x80x94R8xe2x80x94, wherein R8 is selected from direct bond, alkylene and haloalkylene; R9 is selected from direct bond and carbonyl, and R10 is selected from hydrogen, R11xe2x80x94Oxe2x80x94, (R11)2Nxe2x80x94 and R11xe2x80x94(Cxe2x95x90O)xe2x80x94NHxe2x80x94, wherein R11 is selected from hydrogen and organic groups having 1-20 carbons and optionally containing 1-4 heteroatoms selected from oxygen and nitrogen. In a further aspect, R8 is methylene; R9 is carbonyl, and R10 is (R11)2Nxe2x80x94 wherein R11 is selected from hydrogen and organic groups having 1-20 carbons and optionally containing 1-4 heteroatoms selected from oxygen and nitrogen.
In other aspects, the present invention provides a DKP compound of structure (1) wherein R1 is phenyl having a substituent at the position para to the site of attachment to the piperazine ring, and the substituent has the formula 
wherein R12 is selected from hydrogen and organic groups having 1-20 carbons and optionally containing 1-4 heteroatoms selected from oxygen and nitrogen. In a further aspect, R12 is selected from hydrogen, alkyl, heteroalkyl, aryl, heteroaryl, carbocycle aliphatic ring and heterocycle aliphatic ring. The R12 group may, optionally be selected from the following twelve exemplary formulae: 
In other aspects, the present invention provides a DKP compound wherein R1 is phenyl. Optionally, in any of the above-described aspects, n is 1. Optionally, in any of the above-described aspects, R2 and R3 are independently selected from groups of the formula R10xe2x80x94R9xe2x80x94R8xe2x80x94, wherein R8 is selected from direct bond, alkylene and haloalkylene; R9 is selected from direct bond and carbonyl, and R10 is selected from hydrogen, R11xe2x80x94Oxe2x80x94, (R11)2Nxe2x80x94 and R11xe2x80x94(Cxe2x95x90O)xe2x80x94NHxe2x80x94, wherein R11 is selected from hydrogen and organic groups having 1-20 carbons and optionally containing 1-4 heteroatoms selected from oxygen and nitrogen, with the proviso that two R11 groups bonded to the same nitrogen may be bonded together so as to form a heterocyclic ring with the common nitrogen. In one further aspect, R8 is methylene; R9 is selected carbonyl, and R10 is (R11)2Nxe2x80x94. For instance, R10 may be selected from the following twelve exemplary formulae: 
Optionally, in any of the above-described aspects, R4 is xe2x80x94OR5. The R5 may, in one aspect, be selected from hydrogen and alkyl. Optionally, in any of the above-described aspects, and unless otherwise inconsistent, R4 is xe2x80x94NR R7. The R6 may be hydrogen and R7 may be R13xe2x80x94C(xe2x95x90O)xe2x80x94 where R13 is selected from the following twelve exemplary formulae: 
In another aspect, the present invention provides a composition comprising a DKP compound according to any of the aspects described above and herein, and a pharmaceutically acceptable adjuvant, carrier, diluent or excipient.
In another aspect, the present invention provides a method of treating inflammation comprising administering to a subject in need thereof a therapeutically effective amount of a DKP compound as set forth herein.
In another aspect, the present invention provides a method for inhibiting a TNF-xcex1 mediated processes, comprising administering to a patient in need thereof, through a therapeutically or prophylactically acceptable manner, a therapeutically or pharmaceutically effective amount of a composition comprising a DKP compound as set forth herein.
In another aspect, the present invention provides a method for inhibiting a TNF-xcex1. mediated processes, comprising administering to a patient in need thereof, through a therapeutically or prophylactically acceptable manner, a therapeutically or pharmaceutically effective amount of a composition comprising a DKP compound as set forth herein, wherein the administering is selected from, for example, transdermal, oral, intravenous, intramuscular, vaginal, rectal, pulmonary, subcutaneous, sublingual and transmucosal administration.
In another aspect, the present invention provides a method for inhibiting a TNF-xcex1. mediated processes, comprising administering to a patient in need thereof, through a therapeutically or prophylactically acceptable manner, a therapeutically or pharmaceutically effective amount of a composition comprising a DKP compound as set forth herein.
In another aspect, the present invention provides a method for treating a condition associated with an elevated level of NFxcexaB activity in a subject, comprising administering to a subject in need thereof an amount of a DKP compound effective to lower the NFxcexaB activity, wherein the DKP compound is described herein.
In another aspect, the present invention provides a method for treating a condition associated with an elevated level of NFxcexaB activity in a subject, comprising administering to a subject in need thereof an amount of a DKP compound effective to lower the NFxcexaB activity, wherein the DKP compound has the formula (1) as set forth above, according to any of the aspects disclosed herein.
In another aspect, the present invention provides a method of inhibiting IL-8 production in a subject in need thereof comprising administering to the subject an effective amount of a DKP compound as set forth herein.
In another aspect, the present invention provides a method of inhibiting GRO-xcex1. production in a subject in need thereof comprising administering to the subject an effective amount of a DKP compound as set forth herein.
In another aspect, the present invention provides a method for inhibiting a CXCR1 and/or CXCR2 mediated processes, comprising administering to a patient in need thereof, through a therapeutically or prophylactically acceptable manner, a therapeutically or pharmaceutically effective amount of a composition comprising a DKP compound as set forth herein according to any of the aspects of the present invention. In one further aspect, the method inhibits a CXCR1 mediated processes, while in another aspect the method inhibits a CXCR2 mediated processes.
In another aspect, the present invention provides a method for treating an inflammation event, comprising administering to a patient in need thereof, through a therapeutically or prophylactically acceptable manner, a therapeutically or pharmaceutically effective amount of a composition comprising a DKP compound as set forth herein, including any of the aspects of the present invention.
In any of the foregoing methods, the administering may be selected from transdermal, oral, intravenous, intramuscular, vaginal, rectal, pulmonary, subcutaneous, sublingual and transmucosal administration.
In another aspect, the present invention provides a method for identifying a binding partner to a DKP compound according to any of the aspects described herein, comprising: immobilizing proteins known to be involved in the TNF-xcex1 signaling pathway onto a suitable carrier; and passing a solution of said compounds in isolation or mixture over said proteins and analyzing for compound:protein complex formation using surface plasmon resonance (SPR). This method may be conducted in a manner similar to that reported by Karlsson, R et al. Biosensor Analysis of Drug-Target Interactions: Direct and Competitive Binding Assays for Investigation of Interactions Between Thrombin and Thrombin Inhibitors. Anal. Biochem. 2000, 278(1), 1-13. For other examples of identifying small molecule-protein interactions using SPR see the Biacore website at WorldWideWeb.biocore.com.
In another aspect the present invention provides a method for identifying a binding partner to a DKP compound according to any of the aspects disclosed herein, comprising: contacting a cell or cell components with said solid phase compounds in isolation or mixture; removing uncomplexed cellular material, for example by gentle washing with aqueous buffer; and recovering said binding partner from the solid phase compounds. This method may be conducted in a manner similar to that reported by Shimizu, N et al. High Performance Affinity Beads for Identifying Drug Receptors. Nature Biotechnology, 2000, 18(8), 877-881).
These and other aspects of the present invention are described more fully herein, in some instances by reference to the following drawings.